Some compound adjectives pack a whole idea about scope or duration into one hyphenated word. Far-reaching means something has wide influence, and long-lasting means it endures. Keep the hyphen when the word sits right before a noun: a far-reaching decision. One exception to remember: compounds that start with an -ly adverb never take a hyphen, a widely known author, a highly regarded study.
Adjectives that describe scale of impact
far-reaching /ˌfɑr ˈritʃɪŋ/ — The new privacy law had far-reaching consequences for advertisers.
long-lasting /ˌlɔŋ ˈlæstɪŋ/ — Their partnership proved long-lasting, surviving three changes of management.
well-known /ˌwɛl ˈnoʊn/ — She's a well-known expert on coastal erosion.
Not ""The policy will have long reaching consequences." (not an English compound; the pieces don't combine)" — say ""The policy will have far-reaching consequences." (the fixed compound for wide influence)". The word for wide influence is far-reaching, not 'long reaching'. The parts of a compound adjective are fixed, so you can't swap them.
Try it: Which sentence uses the compound adjective for 'wide influence' correctly? (The reforms had far-reaching effects on rural schools. / The reforms had long-reaching effects on rural schools. / The reforms had far reaching effects on rural schools.) Answer: The reforms had far-reaching effects on rural schools. — 'Far-reaching' is the fixed compound meaning wide influence, and it takes a hyphen before the noun 'effects'. 'Long-reaching' isn't an English compound; that idea belongs to 'far-reaching'. 'Far reaching' has the right words but drops the hyphen it needs before a noun.
Try it: Which sentence is punctuated correctly? (She is a well-known author of thrillers. / She is a well known author of thrillers. / She is a well-known, author of thrillers.) Answer: She is a well-known author of thrillers. — Before the noun 'author', the compound needs a hyphen: 'well-known'. After a verb the hyphen is normally dropped, 'The author is well known', because the hyphen's job is to group the words for the noun that follows. Adding a comma after 'well-known' wrongly splits the adjective from the noun it describes.
Adjectives that describe an effect on people
Other compounds describe how something acts on the person experiencing it. Thought-provoking makes you think, eye-catching grabs attention, and time-consuming eats up your time. Each one replaces a whole phrase with a single sharp adjective.
thought-provoking /ˈθɔt prəˌvoʊkɪŋ/ — The documentary raised a thought-provoking question about privacy.
eye-catching /ˈaɪ ˌkætʃɪŋ/ — They gave the campaign an eye-catching design in bright orange.
time-consuming /ˈtaɪm kənˌsumɪŋ/ — Sorting the data by hand turned out to be a time-consuming task.
Not ""That was a time-consuming lecture that really made me reflect." (this says it took a long time, not that it made you think)" — say ""That was a thought-provoking lecture that really made me reflect." (the compound for something that stimulates thinking)". Thought-provoking describes the effect on your mind, while time-consuming only describes how long something takes. Pick the compound by the effect you mean.
Try it: A lecture that makes the audience reflect deeply is best described as: (thought-provoking / eye-catching / time-consuming) Answer: thought-provoking — 'Thought-provoking' means it stimulates thinking, which is exactly the effect of a lecture that makes people reflect. 'Eye-catching' describes something that grabs visual attention, not the mind. 'Time-consuming' just says it takes a long time, which isn't about reflection at all.
Compounds that describe a person
A large family of compound adjectives describes character, and most are built from a noun or adverb plus a past participle. Self-motivated means you get yourself working without being pushed. Level-headed means you stay calm and sensible under pressure. Open-minded means you are willing to consider ideas that are not your own. Down-to-earth means practical and unpretentious, easy to talk to. Two more follow the same shapes: high-profile takes no -ed, because it is built from the noun profile; well-informed takes one, because someone HAS BEEN informed. They go before the noun or after be: a level-headed manager, she is very down-to-earth.
self-motivated /ˌsɛlf ˈmoʊtəveɪtəd/ — We want a self-motivated candidate who does not need chasing.
level-headed /ˌlɛvəl ˈhɛdəd/ — She stayed level-headed while everyone else panicked.
open-minded /ˌoʊpən ˈmaɪndəd/ — A good reviewer is open-minded about unfamiliar approaches.
down-to-earth /ˌdaʊn tu ˈɜrθ/ — For a famous director, he is remarkably down-to-earth.
high-profile /ˌhaɪ ˈproʊfaɪl/ — She took a high-profile role in the campaign.
well-informed /ˌwɛl ɪnˈfɔrmd/ — His answers were well-informed and easy to follow.
Not ""She is a level-head manager."" — say ""She is a level-headed manager."". These compounds end in -ed even when no verb is involved: level-headed, open-minded. Dropping it leaves a noun where an adjective belongs.
Try it: A reference says: "When the server failed an hour before launch, he worked the problem calmly and never raised his voice." Which word fits? (level-headed / self-motivated / open-minded) Answer: level-headed — Staying calm in a crisis is exactly level-headed. Self-motivated would describe starting work without being told, and open-minded would describe accepting other people's ideas. Neither is what the crisis shows.
Compounds that describe a place or a job
The same pattern describes environments. Fast-paced means everything moves quickly and there is little idle time. High-pressure means the stakes and the demands are heavy. Hands-on means you do the work yourself rather than supervising it, so hands-on experience is experience you got by doing. Run-of-the-mill means ordinary, nothing special, and it is mildly negative. Note that hands-on keeps its s: not "hand-on".
fast-paced /ˌfæst ˈpeɪst/ — A newsroom is a fast-paced environment with constant deadlines.
high-pressure /ˌhaɪ ˈprɛʃər/ — Trading is a high-pressure job and burnout is common.
hands-on /ˌhændz ˈɑn/ — The internship gives you hands-on experience with real clients.
run-of-the-mill /ˌrʌn əv ðə ˈmɪl/ — It was a run-of-the-mill conference, nothing I had not heard before.
Not ""The internship gives you hand-on experience."" — say ""The internship gives you hands-on experience."". Hands-on is fixed in the plural. The image is both hands on the work, so the s never drops.
Try it: A course description says students spend every session building circuits themselves rather than watching demonstrations. What is that? (hands-on / run-of-the-mill / high-pressure) Answer: hands-on — Doing the work yourself is hands-on. Run-of-the-mill would call the course ordinary, and high-pressure would say it is stressful. Neither is about who does the building.
Compounds built from a noun plus -ing
Put a noun in front of an -ing form and you get an adjective describing the effect something has on you. Nail-biting means so tense you could chew your nails. Breath-taking means so beautiful or dramatic it stops your breath. Hard-hitting describes a report or film that is blunt and does not soften what it shows. Ground-breaking means it does something nobody has done before. The noun stays singular here: nail-biting, not nails-biting.
nail-biting /ˈneɪl ˌbaɪtɪŋ/ — The final ten minutes of the match were nail-biting.
breath-taking /ˈbrɛθ ˌteɪkɪŋ/ — The view from the ridge was breath-taking.
hard-hitting /ˌhɑrd ˈhɪtɪŋ/ — The documentary is a hard-hitting look at the housing crisis.
ground-breaking /ˈɡraʊnd ˌbreɪkɪŋ/ — Their ground-breaking study changed how the illness is treated.
Not ""The view from the ridge was breath-taken."" — say ""The view from the ridge was breath-taking."". The view TAKES your breath, so the form is -ing. Switching to -taken reverses who is doing what to whom.
Try it: A review says the last ten minutes had the audience gripping their seats, unsure who would survive. Which word fits? (nail-biting / ground-breaking / breath-taking) Answer: nail-biting — Tension and suspense are nail-biting. Ground-breaking would mean nobody had done it before, and breath-taking describes beauty or scale rather than suspense.
Compounds that rank or judge
Some compounds place a thing on a scale. First-rate means excellent, of the highest quality, and second-rate means noticeably poor. Far-fetched means so unlikely you struggle to believe it, which makes it useful for plots and excuses. Action-packed means full of incident from start to finish, and spoiler-filled describes a review that gives away what happens. Watch the pair far-fetched and far-reaching: the first means implausible, the second means its effects spread widely. Longer compounds keep every word of the phrase behind them, articles included: state-of-the-art (the state of the art) and once-in-a-lifetime (once in a lifetime) never drop their the or a.
first-rate /ˌfɜrst ˈreɪt/ — The performances are first-rate throughout.
far-fetched /ˌfɑr ˈfɛtʃt/ — The ending is far-fetched, but the film is still enjoyable.
action-packed /ˈækʃən ˌpækt/ — It is an action-packed thriller with barely a quiet scene.
spoiler-filled /ˈspɔɪlər ˌfɪld/ — Avoid spoiler-filled reviews until you have seen it.
state-of-the-art /ˌsteɪt əv ði ˈɑrt/ — The lab is fitted with state-of-the-art equipment.
once-in-a-lifetime /ˌwʌns ɪn ə ˈlaɪftaɪm/ — It was a once-in-a-lifetime chance to study abroad.
Not ""The ending is far-reaching, but the film is still enjoyable."" — say ""The ending is far-fetched, but the film is still enjoyable."". Far-fetched means hard to believe. Far-reaching means its consequences spread a long way, which is a comment on impact, not on plausibility.
Try it: A reviewer writes that the hero survives a fall from a plane without a scratch. How would they describe that plot point? (far-fetched / far-reaching / first-rate) Answer: far-fetched — Surviving that is hard to believe, which is far-fetched. Far-reaching would say the plot point has wide consequences, and first-rate would praise its quality. Neither comments on plausibility.
Compounds about time and staying power
A last group places something in time. Long-lasting means it continues for a long time, and short-lived is its opposite, over almost as soon as it began. Last-minute describes something done at the final possible moment, and it sits before the noun: a last-minute decision. Old-fashioned means from an earlier style, and depending on tone it is either affectionate or a criticism. Note that short-lived is built on the noun life, so it means having a short life, not being lived shortly.
long-lasting /ˌlɔŋ ˈlæstɪŋ/ — The treaty brought a long-lasting peace to the region.
short-lived /ˌʃɔrt ˈlaɪvd/ — The celebration was short-lived; the result was overturned an hour later.
last-minute /ˌlæst ˈmɪnət/ — A last-minute change to the schedule caught everyone out.
old-fashioned /ˌoʊld ˈfæʃənd/ — He still writes letters by hand, which I find charmingly old-fashioned.
Not ""The celebration was short-lasting."" — say ""The celebration was short-lived."". The opposite of long-lasting is short-lived, not "short-lasting". The pair is irregular and you have to learn both halves.
Try it: A report says the price drop lasted two days before rates went back up. Which word fits? (short-lived / long-lasting / last-minute) Answer: short-lived — Two days and then reversed is short-lived. Long-lasting says the opposite, and last-minute would describe WHEN something was done rather than how long it lasted.